setIndex method
Set index directly (from thumbnail tap or snap resolver).
Implementation
void setIndex(int index) {
if (_state.verticalProgress > 0.01 || itemCount <= 0) return;
final clamped = index.clamp(0, itemCount - 1);
if (clamped != _state.currentIndex) {
_state = _state.copyWith(currentIndex: clamped);
notifyListeners();
}
}